共查询到19条相似文献,搜索用时 156 毫秒
1.
在具有级联光放大器的密集波分复用强度调制一直接检测光纤系统中,导出了包含互相位调制和受激拉曼散射共同作用的强度/相位矩阵表达式。在计算强度噪声谱的基础上,研究了互相位调制和受激拉曼散射的相互耦合并用于密集波分复用系统的噪声分析。在带色散补偿的密集波分复用级联光纤传输系统中(如80信道,信道间距50GHz),受激拉曼散射引入的串扰噪声功率可能超过互相位调制。最后,给出了密集波分复用系统分析与设计的若干建议。 相似文献
2.
3.
偏振模色散及非线性效应对40 Gbit/s密集波分复用系统的影响 总被引:8,自引:0,他引:8
高速率、大容量的密集波分复用系统是光纤通信系统的最终发展方向 ,单信道速率达到 4 0Gbit/s时 ,光纤的非线性效应、偏振模色散现象对系统的影响更加突出。在综合考虑群速度色散、自相位调制、交叉相位调制、四波混合、偏振模色散等因素的基础上 ,推导了密集波分复用系统中任意信道的耦合非线性薛定谔方程组。利用扩展的分步傅里叶方法对该方程进行了数值计算 ,通过对 8× 4 0Gbit/s密集波分复用系统的仿真 ,分别研究了非线性效应和偏振模色散对密集波分复用系统的影响。发现由于交叉相位调制和四波混合作用 ,多波长的密集波分复用系统比单波系统受非线性效应影响严重 ;系统受偏振模色散与非线性效应的影响程度与输入信号功率有关 ,在入射光单信道平均功率较低 0 .1mW时 ,偏振模色散是影响系统性能的主要因素 ;当入射光单信道平均功率较高1mW时 ,系统受非线性效应影响严重。而偏振模色散在使信号脉冲展宽的同时 ,类似于非零色散位移光纤中的微小色散 ,对非线性效应又有一定的抑制作用。 相似文献
4.
5.
6.
7.
8.
9.
集总式放大链路中,放大器的周期分布,等效于形成一折射率光栅,它为四波混频提供了相位匹配的条件,产生边带不稳定性.本文通过解析和数值模拟的方法,研究了周期集总式放 大链路中,交叉相位调制边带不稳定性.解析研究中,根据耦合方程的稳态解,计算了反常 色散与正常色散光纤链路中由于扰动而产生的边带不稳定性的增益;数值模拟中,利用分裂 步长傅里叶变换法与Monte_Carlo方法,得出了输出光脉冲的频谱,说明输出光脉冲频谱中 产生新的边带.两种方法的计算结果表明,在周期集总式放大光通信链路中,存在交叉相位 调制边带不稳定性,两种方法得到的结论基本一致.
关键词:
交叉相位调制
边带不稳定性
集总式放大 相似文献
10.
提出了在波分复用光纤通信系统中,考虑光纤色散“走离”时受激喇曼散射(SRS)信道的新模型,给出了计算中距离步长的选取公式。根据该模型,数值计算了各信道在随机数字序列调制下和在受激喇曼散射(SRS)非线性效应作用下经过有色散“走离”的波分复用光纤系统的传输功率。得出光纤色散会降低SRS效应引起的输出功率波动的结论,画出了在SRS效应作用下输出功率标准差随色散系数变化的曲线,并对产生该现象的机理进行了定性分析。该模型适合于任意光纤色散、任意输入功率和任意信道数目。 相似文献
11.
12.
13.
研制了一种基于掺Yb3+的双包层大模场面积偏振光子晶体光纤的耗散孤子锁模激光器.利用数值模拟分析了光纤激光器中耗散孤子动力学过程,与全正色散锁模激光器相比,脉冲窄化机理更加丰富,半导体可饱和吸收镜(SESAM)的非线性吸收,啁啾脉冲的光谱滤波以及光纤的增益色散同时起作用,这些因素使耗散孤子锁模更加容易实现,并且稳定运行.其中,光谱滤波的耗散过程是稳定锁模机制的主导因素,滤波片能够在频域和时域同时窄化脉冲,并且去除脉冲啁啾,限制脉冲在腔内始终小于1ps.在实验上实现了无色散补偿腔中直接输出脉冲宽度777fs,最高平均功率达到1W,重复频率48·27MHz,对应单脉冲能量20nJ的飞秒激光. 相似文献
14.
15.
In direct sequence-optical code division multiplexing access (DS-OCDMA) system networks, data rate and data spreading technique involved in such systems require a high chip rate. Transmission link in these systems is significantly affected by the fiber chromatic dispersion. In this study, we have developed and employed a simple model to estimate the G652 fiber dispersion effects. OCDMA technique has been employed to investigate fiber chromatic dispersion effects on multiple access interference (MAI). We have found that, at a short optical fiber length, the optical fiber dispersion has a significant impact on the high data rate transmission systems (higher than 750 Mbit/s). The performance and optimization of optical orthogonal code (OOC) in the OCDMA system is reported. We have demonstrated that, for a high data rate, even if dispersion compensated devices are not deployed, the BER can be significantly improved when the OOC desired length is selected. We have shown that when compensation dispersion devices are not deployed in the system, there is a trade off between the limited dispersion effects and the MAI. 相似文献
16.
Abstract This article presents a feasibility study for using a hybrid cladding photonic crystal fiber as a distributed fiber Raman amplifier based transmission link with negligible confinement losses and flattened dispersion characteristics. The simulation results clearly indicate that a bit error rate of 10?9 can be maintained at the end of a (4 × 170)-km distributed fiber Raman amplifier link operating with 40 Gbps and 0.6 dBm transmit power if 20 dBm of pump power is used for each span. 相似文献
17.
18.
Disintegration of a soliton in a dispersion-managed optical communication line with random parameters 总被引:15,自引:0,他引:15
The propagation of dispersion-managed solitons in optical fiber links with a random dispersion map has been studied. Two types of randomness are considered:random dispersion magnitudes and random lengths of the spans. By numerical simulations, disintegration of a soliton propagating in such an optical communication line is shown to occur. It is observed that the stability of the soliton propagation is affected more by modulations of the dispersion magnitudes of the spans than by modulations of the span lengths. Results of numerical simulations of the soliton breakup distance confirm theoretical predictions in the averaged dynamics limit. 相似文献
19.
We numerically investigate and compare the performance of fiber nonlinearity compensation using digital back propagation (DBP) method and pilot-aided method in coherent optical transmission systems using different fiber links. Simulations for wavelength division multiplexed (WDM) 112 Gb/s polarization division multiplexed quadrature phase shift keying (PDM-QPSK) systems with dispersion unmanaged (no DM) and dispersion managed (DM) fiber links are implemented. System Q-factor and maximum transmission distance at bit error rate (BER) of 3.8 ÿ 10?3 are calculated for performance comparison. The results show that, for system with no DM fiber link, DBP method outperforms pilot-aided method, because DBP method has better performance for intra-channel fiber nonlinearity compensation. However, for system with DM fiber link where inter-channel fiber nonlinearity plays an important role, pilot-aided method performs better than DBP method, because of its ability for inter-channel fiber nonlinearity compensation. 相似文献